1. Field of the Invention
The present invention relates in general to a dynamic damper serving as a dynamic vibration absorber, and a method of manufacturing the same. More particularly, the invention is concerned with such a dynamic damper which is to be attached to a rotary shaft, such as a drive shaft of a motor vehicle, for damping or absorbing vibrations of the rotary shaft, and a method of manufacturing the same.
2. Discussion of the Related Art
There is known a dynamic damper, as disclosed in JP-Y2-02-31626 and JP-A-08-28627, for damping vibrations which are applied to a rotary shaft such as a drive shaft of a motor vehicle in an axial direction of the rotary shaft as well as in a direction perpendicular to the axial direction. The dynamic damper includes a matallic mass member which has a generally cylindrical shape, and an elastic support member which is to be mounted on the rotary shaft. The elastic support member elastically supports the metallic mass member with respect to the rotary shaft such that the mass member is displaceable relative to the rotary shaft as the elastic support member is mounted on the rotary shaft. The thus constructed dynamic damper minimizes transmission of the vibrations and noises of the rotary shaft to the other components, and also restrains a stress amplitude of the rotary shaft for thereby effectively preventing fatigue failure of the rotary shaft.
In recent years, there is a demand for further improved efficiency and further reduced cost of manufacture of the dynamic damper. To meet such a demand, there are required some improvements in the construction of the dynamic damper.